Technical Field
The present invention relates to a substrate processing method, a substrate processing apparatus, a method of manufacturing a semiconductor device and a non-transitory computer-readable recording medium.
Description of Related Art
Technical difficulties have been increased in a processing technique of controlling a leakage current interference between transistor devices, with miniaturization of a large-scale integrated circuit (Large Scale Integrated Circuit: called simply LSI hereafter). Elements in the LSI are isolated by a method of forming a gap such as a groove or a hole, between the elements to be separated which are provided adjacent to each other on a silicon (Si) as a substrate, and depositing an insulating material in this gap. An oxide film is frequently used as the insulating material, and for example, a silicon oxide film (SiO film) is used.
The SiO film can be formed by oxidation of a Si substrate itself, Chemical Vapor Deposition (CVD method), or Spin On Dielectric (SOD method), etc.
With a progress of miniaturization of recent years, when oxide is embedded into a fine structure, and particularly when oxide is embedded into a gap structure deep in a vertical direction and narrow in a horizontal direction, an embedding method by CVD has a technical limit. Under such a circumstance, an embedding method using an oxide having fluidity, that is, using an SOD method, has been more frequently employed. In the SOD method, a coating insulating material containing an inorganic or organic component called SOG (Spin On Glass) is used. Although this material is employed in the manufacturing step of LSI prior to emergence of a CVD oxide film, a processing size is simply about 0.35 μm to 1 μm according to a processing technique using the SOD method. In order to realize the miniaturization, a reforming step of applying heat treatment of about 400° C. in a nitrogen atmosphere for example, is performed after coating of this material.